VERMICOMPOST REMEDIATION OF CONTAMINATED SOIL: A MINI REVIEW

Abstract

The remediation of contaminated soil via vermicomposting and the advantages of the remediation process were reviewed. The reviewed was aimed at presenting the vermicomposting process of remediating soils contaminated with heavy metals, organic matters and hydrocarbons. Vermicomposting have been beneficial in decontaminating agueous media by adsorbing or degrading pollutants, increasing soil fertility and agricultural productivity and promoting the biocontrol of agricultural disease. This mini-review indicates that vermicomposting isa promising low-cost and environmentally friendly way oftreating contaminated soils.

Headnote

Abstract: The remediation of contaminated soil via vermicomposting and the advantages of the remediation process were reviewed. The reviewed was aimed at presenting the vermicomposting process of remediating soils contaminated with heavy metals, organic matters and hydrocarbons. Vermicomposting have been beneficial in decontaminating agueous media by adsorbing or degrading pollutants, increasing soil fertility and agricultural productivity and promoting the biocontrol of agricultural disease. This mini-review indicates that vermicomposting isa promising low-cost and environmentally friendly way oftreating contaminated soils.

Keywords: vermicompost, remediation, earthworm, contaminated soil

1. INTRODUCTION

The soil have always been contaminated with huge volume of waste, heavy metals and oily sludge from the domestic and industrial production and processing of various materials. These contaminants are made up of deleterious components, hydrocarbons and heavy metals (Koolivandet al., 2020). Organic contaminants, sludge and heavy metals are contributor to soil degradation which also affect human and animal heath as a result of their accumulation in food chain (Yoon et al., 2006; Belliturket al., 2015), as well as decrease the quality of the soil for crop growth and the activities of soil organisms (Sunithaet al., 2014). Most heavy metals are deposited mainly on the soil where they exhibit theirtoxic effects on the soil which in turn affect several physiological plant processes (Jadía and Fulekar, 2008), as well disturb enzymatic process and increase plant predisposition to fungal invasion (Kabata-Pendias and Pendías, 2001).

Remediation of contaminated soil involves thorough treatment of the soil which may be physical, chemical or biological process. Several process have been utilized for soil remediation such as soil vapor extraction, freed product recovery, solvent extraction, incineration, activated carbon adsorption, aeration towers and bioreactors (Dores-Silva et al., 2019). Nevertheless, majority of these remediation processes are associated with extended periods of exposure and high clean ups cost (Mohan et al., 2006).Bioremediation processes such as vermicomposting are effective for remediating contaminated soil as they are economically viable (Mohammed and Abubakar, 2015) although they are limited by factors such as types of microorganism used, temperature, pH of the soil and bioavailability of the contaminants (Garcia-Sanchez et al., 2018).

Natural humidification of the soil is a slow process which produces humic matter accelerated by composting organic residues (Pereira et al., 2014). Composting is an environmental process used in recycling waste materials, destroying the pathogens in the waste, converting nitrogen into stable organic forms, decreasing the volume of the waste and improving the physicochemical characteristics of the residues (Pereira and Arruda, 2003). Contrary to composting, vermicomposting involves the use of earthworms for metabolizing organic debris by softening of the residues with the animal's saliva, neutralization of the calcium excreted from the innerwalls of the animal's esophagus, grinding the residue particles in their muscular gizzard, digesting of the organic material by proteolytic enzymes present in their stomach and the decomposition of the mashed organic particles through the activities of enzymes such as amylases, proteases and lipases (Pereira and Arruda, 2003; Forneset al., 2012). This biochemical process results to the excretion of vermicompost which when allowed for a period of six months, matured continuously, increasing the humid compound in order to achieve stabilization of the organic matter (Landgrafet al., 1998; Pereira et al., 2014).

Vermicomposting is a mesophilic transformation in which the resulting material is made up of structural properties that aid in facilitating aeration and retaining water (Bellturket al., 2015), thus increasing the cation exchange capacity of the soils and enhancingthe adsorption of positive ions (Herwijnenet al., 2007). This remediation process enhances plant growth, aid in phytoremediation as well as immobilize metal pollutants (Bellturket al., 2015). The earthworms which are bioaccumulators bioremediate the metal contents of the compost generated from the waste materials (Pattnaik and Reddy, 2012). The porous nature of vermicompost materials as shown in the Screening Electron Micrograph (SEM) (Figure 1) enhances the adsorptive characteristics of the process. The adsorptive potentials of the vermicomposting process is observed in the numerous hydrophilic groups (such as -OH, -COOH, -SH etc.) (Figure 2) present in the humidified material, the high surface area and the vast porosity of the material (Pereira et al., 2014).

Owing to the fact that vermicomposting increases the humic acid content of the soil as well as emits lesser quantities of atmospheric pollutants, it is considered more beneficial than composting. According to Nagavallemma et al., (2006), vermicompost accumulates higher levels of organic macro and micronutrients such as Carbon, Nitrogen, Phosphorus, Potassium, Calcium, Zinc, Magnesium, Sodium, Iron, Manganese and Copper. Also Busatoet al., (2012) observed that these plant nutrients exhibit greater availability when vermicompost is applied to the soil. Thus, vermicomposting is considered an environmentally friendly amendment technique for contaminated soils and adopted by researchers forthe treatment of contaminated soil. Liu et al., (2019) observed in their studies that the adsorption of metals onto vermicompost and an increase in soil pH afterthe vermicompost amendment of the soil, are possibly responsible forthe decreased availability of Cd, NI, and Cr in the contaminated soil.

2. VERMICOMPOSTING PROCESS

Vermicomposting process which involves the breaking down of the waste matter (Dominguez, 2004) begins in the gizzard of earthworms where the waste is digested in the guts of the earthworm by enzymes and microorganisms (Grasserovaet al., 2020). This process can result to the removal of pollutant from the soil thus known as vermiremediation (Rodríguez-Campos et al., 2014). According to Shi et al. (2019), vermicomposting is one of the vermiremediation processes which also include vermitransformation, vermiaccumulation, vermiextraction and drilodegradation. Several researchers have used these processes in the removal of micro-pollutants and heavy metals from the soil (Aziziet al. 2013; Sutharet al. 2014; Chachinaet al. 2016; He et al. 2016; Chevillotet al. 2017; Havraneket al. 2017; Roratet al. 2017; Lin et al. 2019; Owagboriaye et al. 2020). The earthworms present in the soil reduced the waste by grinding them into smaller particles thereby increasing the availability for microorganisms (Grasserovaet al., 2020). Earthworms can also accumulate heavy metals such as cadmium and zinc in their soft tissue which they can transform into valent state making them less toxic and more available for plant. Studies have also shown that earthworm increases the activity of the detoxification of enzymes cytochrome P450 and glutathione-S-transferase by ingesting them into their tissues thereby degrading and detoxifying them (Achaziet al. 1998; Zhang et al. 2009; Zhao et al. 2020).

The physical and biochemical activities of the earthworm leads to the rapid ingestion and degradation of the waste matter within a shorter period of time into the tissues of the earthworm (Dores-Silva et al., 2019) results to the creation of a high quality compost materials which are rich in essential elements required by plants such as phosphorus (P), nitrogen (N), sulfur (S), potassium (K) and magnesium (Mg) (RodríguezCampos et al., 2014; Brinzaet al., 2014). Nagavallemmaet al. (2006) in their study showed the accumulation of the macro and micronutrients; nitrogen, calcium, phosphorus, organic carbon, sodium, zinc, copper, iron, and manganese via vermicomposting. Owing to the increase in the humic acid content and emission of atmospheric pollutants during vermicomposting, it is considered more beneficial than other bioremediation processes (Pereira et al., 2014). The process as exhibit greater availability of crop nutrient when used in soil remediation (Busatoet al., 2012).

The study by Nagavallemmaet al. (2006) showed that vermicomposting is usually carried out in pits dug deep into the soil below the ground although most times vermicomposting on the soil surface has also be conducted successfully. The process can also be conducted in containers of tanks made up of several materials such as local rocks, hollow bricks, cement rings, among others (Pereira et al., 2014). During vermicompost processing, the waste deposited on the soil is allowed to mix with earthworm. Different kinds of soils can also be added to the mixture thus enhancing the presence of high contents of kaolinite, feldspar, quartz and other essential minerals present in the composition (Pereira, 2000).Releasing of the earthworm into the soil for decomposition is best done when the temperature is near 25°C (Nagavallemmaet al. (2006)). At this temperature, the atmosphere is humid, and conducive for the activities of the earthworm thereby facilitating the breaking down and degradation process.

3. HARMFUL COMPONENTSOFCONTAMINATED SOILS

Soil contamination is a global problem that constitutes significant threat to human and environmental health both in the present and in the future. Soil contamination has been an important topic in many areas of research, practice and policy within different countries which has also been extended internationally (Troeh, Hobbs, & Donahue, 1981). The attached importance to contaminated soil has been increasing over the years. Increased population growth and industrialization around the world are key factors responsible for the increase in the contamination of soil and the environment which negatively affects various human health, wildlife, and microorganisms. The contaminant sources are waste disposal sites, mining sites, crude oil refineries and exploration, chemical application in agriculture, use of wastes water for irrigation, industrial emissions and maintenance (Zhan, et al., 2013).

Contaminant can be any element that has the potential of causing harm on the environment. Environmental contamination is primarily interested in the physical, chemical or biological agents or their combinations that may pose a threat to life, health, safety or welfare of organisms in the environment. Soil contamination is the existence of these contamination above permissible limits at which deterioration or loss of soil functions occur(Cottenie & Verloo , 1984). Major areas of soil contamination and pollution have been highlighted by Blum (1990) as follows:

* Radioactive pollution of the soil. Accidental release of radioactive substances has been discovered in some part of the world. The substances are very harmful to the soil and provide an unsafe environment for human life and living organisms. There is currently serious concern over the risk of soil pollution on food safety and the sustainability of agricultural production across the globe. Fears of the food chain being compromised by soil pollutants are eminent as the consumption of food crops contained with pollutants remained a major suspect in food poison. Several studies have linked serious human health challenges to heavy metal accumulation by plants from contaminated soils (Lente , Keraita , Drechsel, Ofosu-Anim, & Brimah, 2012; Muchuweti, et al., 2006; Khan , Cao, Zheng, Huang, & Zhu, 2008; Zhuang , McBride. Xia. Li. & Li. 2009)

* Soil acidification through the accumulation of acid from phosphate fertilizer, carbon, nitrogen and Sulphur cycles, and acid rains. Soil acidification lowers the soil pH and alters the soil chemistry. When the soil pH is reduced, the bioavailability of heavy metals in the soil is increased and a harmful environment for biological activities is created, the breakdown of nutrients for plant uptake is also hindered and the food chain compromised.

* Direct introduction of toxic elements and compounds such as petroleum hydrocarbon and other dangerous organic compounds. This contributes to making the soil unsafe and creates an impediment in its functions.

Petroleum hydrocarbon is a complex substance formed from hydrogen and carbon molecules and sometimes containing other impurities such as oxygen, Sulphur, and nitrogen, heavy metals and oxygen compounds. Examples of petroleum hydrocarbon contaminants are total petroleum hydrocarbons (TPHs) and Polycyclic aromatic hydrocarbons (PAHs). Soil contamination with petroleum hydrocarbons is one of the adverse environmental problems associated with crude oil exploration in any part of the globe. Natural gas, Crude oil, tars and asphalt are types of petroleum hydrocarbons (Frick, Famell, & Germida, 1999). Total petroleum hydrocarbons (TPHs) are used to describe mixture of organic compounds found in or derived from crude oil that has the potential to be very toxic (CCME, 2001). Total petroleum hydrocarbons can generally be divided into three fractions: (i) aliphatic, (ii) aromatics and (¡¡i) polar and asphaltenes(Kang, Park, Jung, & Park, 2009). When soil is contaminated by petroleum hydrocarbons, the soil will have insufficient aeration due to the displacement of air from the spaces or pores between the soil particles. The displacement of air in the soil pores by petroleum hydrocarbons will cause anaerobic environment in soil by smothering soil particles and blocking air diffusion in the soil pores and affect the soil microbial communities negatively (Townsend, Prince, & Suflita , 2003: Labud , Garcia, & Hernandez , 2007: Sutton , et al., 2013)

Most product that contain total petroleum hydrocarbons (TPHs) are naturally volatile. Some are clear or light colour liquids that evaporate easily and others, arethick, dark liquids or semisolid that do not evaporate and many of these products (gasoline, kerosene, etc.) have oily odours (Ciller, Witter, & McGrath, 1998). The composition of petroleum hydrocarbons (PHCs); varies slightly by its source, but the toxic properties are consistent. Chemicals such as benzene and polycyclic aromatic hydrocarbons (PAHs) are extremely toxic components of serious

4. UTILIZATION OF VERMICOMPOSTING IN CONTAMINATED SOILREMEDIATION

Humidified adsorbent have been adopted for the immobilization of soil contaminants such as heavy metals. The remediation of polluted soils using vermicompost processes depend on several factors such as the particle size of the soil, the structural characteristics of the clay present in the soil, the quantity and quality of the humic segment of the vermicompost, the chemical and the physical properties of the pollutants to be degraded (Pereira et al., 2014). These qualities aid in decreasing the level and mobility of the dangerous chemicals present in the polluted soils.

Delgado-Moreno and Pena (2009) adopted vermicomposting process for the reduction of the herbicide [3-(3,4-dichlorophenyl)-l,l-dimethylurea, or diuron] in soils. Thediuron (C₉H₁₀C₁₂N₂O exhibits reasonable polarity, thus there was considerable affinity between this compound and the hydrophilic groups of the vermicompost, with the consequent distribution of diuron through different horizons of amended soils. The vermicompost used by Delgado-Moreno and Pena (2009) was derived from olive cake to the herbicide contaminated soil. The calcareous soil was mixed with vermicompost and other substrates at rates four times higherthan the agronomic recommended dose. Observation showed that the biological degradation of the herbicides increased during the first week of incubation, but residual concentrations of all herbicides (simazine, terbuthylazine, cyanazine, and prometryn) were similar between the non-treated and treaed soils. Owing to this, vermicompost increased the kinetics of herbicide decomposition (by means of microbial biostimulation), but it did not act on the thermodynamic aspect.

Similarly, Fernandez-Bayoet al. (2007) studied the effect of vermicompost on imidacloprid (C₉H₁₀ClN₅O2) insecticide mobility of many Spanish soils. The vermicompost successfully reduced and degraded the imidacloprid releasing the polluted substance. As expected from considerations of polarity, vermicompost was responsible for substantial retention of imidacloprid, as observed for diuron (Delgado-Moreno and Pena, 2OO9).Kadian et al., (2012) in their study detected that the concentrations of different pesticides decreased in the soil after being treated with vermicompost. The microorganism stimulating ability of the vermicompost was the main cause of the pesticide decomposition. The study by Iwamoto and Nasu(2OOl) showed that the in order to establish bioremediation in soils, one of the important criteria to consider is the organic amendment ability of the biostimulating microorganisms to be used for the remediation process.

Alvarez-Bernal et al.(2006) removed Polycyclic Aromatic Hydrocarbons (PAHs) using vermicompost although the consequence of the experiment was high residual of phenanthrene, anthracene and benzo(a)pyrene present in the soil. In a study by Contreras-Ramos et al. (2008), earthworms and biosolids were employed, in the extraction of Polycyclic Aromatic Hydrocarbons (PAHs) from polluted soils. The vermicompost showed low effectiveness in the remediation process which could be attributed to the weak polarity of PAHs. This tends to nullify the thermodynamic tendency of transferring these organic pollutants to the vermicompost (Pereira et al., 2014).

Jordao et al. (2Oll)in their study to minimize the heavy metalssoil pollution, added vermicompost to tropical soils in order to decrease the mobility of Cd2+ and Cu2+. The authors achieved satisfactory results, which was as a result of the accentuated spontaneity related to adsorptive processes (AG around -14,000 kJimol-1). Their work also showed that vermicompost is able to bioremediate metallic contaminated soils containingand this ability is also extended to other organic substrates (Kavamura and Esposito, 2010). According to Park et al. (2011), bioremediation of metals by organic substrates is as a result of the immobilization, reduction, volatilization, and modification of the rhizosphere.

Furthermore, vermicompostretain ionic species through adsorptive mechanism in terms of immobilization. This mechanism aid the process in the bioremediation of heavy metals such as Cd2+ and Cu2+ as studied by Jordao et al. (2011). Vermicompost also remediates the soil through reduction process as it serves as a source of electron and carbon forreducing microorganisms (Pereira et al., 2014). Also remediation of heavy metal contaminated soils through volatilization process can also be carried out using vermicompost due to the microbiological methylation of some group of elements which include Se, As and Hg. The microorganisms present in the vermicompost play essential role in the methylation and reduction reactions and thus provides substantial microbiota to the soil which stimulates the microbial population of the soil. (Park et al. (2011).

Vermicompost cannot only be considered as a source of microorganisms to soils but also as a supply of nutrients for the native microbiota of these ecosystems. Studies have showed that soils polluted with different herbicides (Delgado-Moreno and Pena, 2009, Fernandez-Bayoet al., 2009) had their microbial populations restored after the addition of vermicompost. In these specific cases, the greater part of the microbiota from the vermicompost was fixed to the soil (Pereira et al., 20l4).Vermicompostsand diverse other organic amendments release weak acids (citric, maleic, lactic, oxalic, propanoic, and butyric acids, among others) to soils. This reduction in soil pH has profound consequences on the chemistry and biology of these ecosystems, especially in the rhizosphere that comprises the area immediately around the roots (Kavamura and Esposito, 2010). In this case, bioremediation is improved by excess of H3O+ in soil solution which stimulates the transfer of metallic pollutants to plants. This situation is clearly desirable only for plants devoted to removal of hazardous metals from polluted soils.

5. CONCLUSION

Microorganisms are known to be responsible for biochemical degradation of waste matter, but vermicomposting is essentially influenced by the physical and biochemical activities of earthworms, whose line of action is to ingest the waste matter thereby creating a high quality compost resulting in a rich material with essential elements for plants. Vermicomposting have been beneficial in decontaminating aqueous media by adsorbing or degrading pollutants, increasing soil fertility and agricultural productivity and promoting the biocontrol of agricultural disease. Vermicomposting has been successfully used for removing polycyclic aromatic hydrocarbons, organic wastes and heavy metals. This mini-review indicates that vermicomposting is a promising low-cost and environmentally friendly way of treating contaminated soils.

References

References

[1] Pereira, M. G. and Arruda, M. A. Z. (2003). "Vermicompost as a natural adsorbent material: characterization and potentialities for cadmium adsorption," Journal of the Brazilian Chemical Society, vol. 14, no. 1, pp. 39-47.

[2] Pereira, M. G., de Souza Neta, L. C., Fontes, M. P. F., Souza, A. N., Matos, T. C., Sachdev, R. L.., dos Santos, A. V., da Guarda Souza, M. 0., Santana de Andrade, M. V. A., Paulo, G. M. M., Ribeiro, J. N. and Ribeiro, A. V. F. (2014). An Overview of the Environmental Applicability of Vermicompost: From Wastewater Treatment to the Development of Sensitive Analytical Methods. 3e Scientific World Journal, 1 -14

[3] F. Fornes, D.Mendonza-Hernandez, R. Gracia-de-la-Fuente, M. Abad, and R. M. Belda, "Composting versus vermicomposting: a comparative study of organic matter evolution through straight and combined processes," Bioresource Technology, vol. 118, pp. 296-305,2012.

[4] M. D. Landgraf, S. C. Da Silva, and M. 0. 0. Rezende, "Mechanism of metribuzin herbicide sorption by humic acid samples from peat and vermicompost," Analy ticaCh im ica Acta, vol. 368, no. 1-2, pp. 155-164,1998.

[5] Herwijnen RV, Hutchings TR, Al-Tabbaa A, Oojt AJ, Johns ML, (2007) Remediation of metal contaminated soil with mineral-amended composts. Environmental Pollution: 347-354.

[6] Bellturk, K., Shreetha, P. and Gorres, J. H. (2015). The Importance of Phytoremediation of Heavy Metal Contaminated Soil Using Vermicompost for Sustainable Agriculture. J Rice Res 2015,3:2

[7] Pattnaik S, Reddy MV (2012) Remediation of heavy metals from urban waste by vermicomposting using earthworms: Eudriluseugeniae, Eiseniafetida and Perionyxexcavatus. International Journal of Environment and Waste Management 10:284-296

[8] VanLoon, G. W. and Duffy, S. J. (2005). Environmental Chemistry-A Global Perspective, Oxford University Press, Oxford, UK, 2nd edition.

[9] K. P. Nagavallemma, S. P. Wani, L. Stephane, "Vermicomposting: recycling wastes into valuable organic fertilizer," SAT e-JournaI, vol. 2, pp. 1-16,2006.

[10] J. G. Busato, L. S. Lima, N. 0. Aguiar, L. P. Canellas, and F. L. Olivares, "Changes in labile phosphorus forms during maturation of vermicompost enriched with phosp ho russol ubi I íz ing and diazotrophic bacteria," Bioresource Technology, vol. 110, pp. 390-395,2012

[11] Koolivand, A., Saeedi, R., Coulon, F., Kumar, V., Villasenor, J., Asghari, F. and Hesampoor, F. (2020). Bioremediation of petroleum hydrocarbons by vermicomposting process bioaugmentated with indigenous bacterial consortium isolated from petroleum oily sludge. Ecotoxicologyand Environmental Safety. 198; 110645

[12] Yoon J, Cao, X, Zhou, Q, Ma, LQ (2006) Accumulation ofPb, Cu, and Zn in Native Plants Growing on a Contaminated Florida Site. Sei. Total Environ. 368:456-464.

[13] Belliturk, K., Shrestha, P. and Gottes, J. H. (2015). The Importance of Phytoremediation of Heavy Metal Contaminated Soil Using Vermicompost for Sustainable Agriculture. J Rice Res 2015,3:2

[14] Sunitha R, Mahimairaja S, Bharani, A, Gayathri P (2014) Enhanced Phytoremediation Technology for Chromium Contaminated Soils using Biological Amendments. International Journal of Science and Technology, 3:153-162.

[15] Dotes-Silva, P. R., Cotta, J. A., Landgraf, M. D. and Rezende, M. 0. (2019). The application of the vermicomposting process in the bioremed ration of diesel contaminated soils. Journal of Environmental Science and Health, Part B. 1 - 8

[16] Garcia-Sanchez, M.; Kosnar, Z.; Metci, F.; Atanda, E.; Tlustos, P. A comparative study to evaluate natural attenuation, mycoaugmentation, phytoremediation, and microbial-assisted phytoremediation strategies for the bioremediation of an aged PAH-polluted soil. Ecotoxicol. Environ. Saf. 2018,147,165-174.

[17] Mohan, S. V.; Kisa, T.; Ohkuma, L; Kanały, R. A.; Shimizu, Y. Bioremediation technologies for treatment of РАН-contaminated soil and strategies to enhance process efficiency. Rev. Environ. Sei. Biotechnol. 2006,5,347-374.

[18] Mohammed, M. C.; Abubakar, S. I. Bioremediation and biodegradation of hydrocarbon contaminated soils: a review. OSR J. Environ. Sei. Toxicol. Food Technoi. (IOSR- JESTFT). 2015,9,2319-2402. D

[19] Azizi AB, LimMPM, NoorZM, Abdullah N (2013) Vermiremoval of heavy metal in sewage sludge by utilisingLumbricusrubellus. Ecotoxicol Environ Saf 90:13-20

[20] Owagboriaye F, Dedeke G, Bamidele J, Aladesida A, Isibor P, Feyisola R, Adeleke M (2020) Biochemical response and vermiremediation assessment of three earthworm species (Alma millsoni, Eudriluseugeniae and Libyodrilus violaceus) in soil contaminated with a glyphosate-based herbicide. Ecol Indic 108:105678.

[21] Suthar S, Sajwan P, Kumar К (2014) Vermiremediation of heavy metals in wastewater sludge from paper and pulp industry using earthworm Eiseniafetida. Ecotoxicol Environ Saf 109:177-184

[22] Rorat A, Wloką D, Grobelak A, Grosser A, Sosnecka A, Milczarek M, Jelonek P, Vandenbulcke F, Kacprzak M (2017) Vermiremediation of polycyclic aromatic hydrocarbons and heavy metals in sewage sludge composting process. J Environ Manage 187:347-353.

[23] Lin Z, Zhen Z, Liang Y, Li J, Yang J, Zhong L, Zhao L, Li Y, Luo C, Ren L (2019) Changes in atrazine speciation and the degradation pathway in red soil during the vermiremediation process. J Hazard Mater 364:710-719

[24] He X, Zhang Y, Shen M, Zeng G, Zhou M, Li M (2016) Effect of vermicomposting on concentration and speciation of heavy metals in sewage sludge with additive materials. BioresourTechnol 218:867-873.

[25] Havranek I, Coutris C, Norii HR, Rivier PA, Joner EJ (2017) Uptake and elimination kinetics of the biocide triclosan and the synthetic musksgalaxolide and tonalide in the earthworm Dendrobaenaveneta when exposed to sewage sludge. Environ ToxicolChem 36:2068-2073

[26] Chachina SB, Voronkova NA, Baklanova ON (2016) Biological remediation of the petroleum and diesel contaminated soil with earthworms Eiseniafetida. Procedía Eng 152:122-133.

[27] Chevillot F, Convert Y, Desrosiers M, Cadoret N, Veil leux É, Cabana H, Bel lenger JP (2017) Selective bioaccumulation of neonicotinoids and sub-lethal effects in the earthworm Eiseniaandrei exposed to environmental concentrations in an artificial soil. Chemosphere 186:839-847

[28] Grasse rová. A., Hanč, A., I n nema n ová, P., Cajthaml, T. (2020). Composting and vermicomposting used to break down and remove pollutants from organic waste: amini review European Journal of Environmental Sciences, Vol. 10, No. 1, pp. 9-14

[29] Dominguez J (2004) State-of-the-art and new perspectives on vermicomposting research. In: Earthworm Ecology (2nd Edition). CRC Press, USA, pp 401-424.

[30] Achazi RK, Flenner C, Livingstone DR, Peters ED, Schaub K, Scheiwe E (1998) Cytochrome P450 and dependent activities in unexposed and РАН-exposed terrestrial annelids. Comp BiochemPhysiol C Phar macolToxicol E nd ocr in о 1121:339-350

[31] Zhang X, Lu Y, Shi Y, Chen C, Yang Z, Li Y, Feng, Y (2009) Antioxidant and metabolic responses induced by cadmium and pyrene in the earthworm Eiseniafetida in two different systems: contactând soil tests. ChemEcol 25:205-215.

[32] Zhao S, Wang B, Zhong Z, Liu T, Liang T, Zhan J (2020) Contributions of enzymes and gut microbes to biotransformation of perfluorooctane sulfonamide in earthworms (Eiseniafetida). Chemosphere 238:124619.

[33] Rodríguez-Campos, J.; Dendooven, L; Alvarez-Bernal, D.; Contreras-Ramos, S. M. Potential of earthworms to accelerate removal of organic contaminants from soil: a review. Appl. Soil Ecol. 2014,79,10-25.

[34] Brinza, L; Schofield, P. F.; Hodson, M. E.; Weller, S.; Ignatyev, K.; Geraki, K.; Quinn, P. D.; Mosselmans, J. F. W. Combining mXANES and mXRD mapping to analyse the heterogeneity in calcium carbonate granules excreted by the earthworm Lumbricusterrestris. J. Synchrotron Rad. 2014,21,235-241.

[35] Dores-Silva, P. R., Cotta, J. A. 0., Landgraf, M. D. &Reze nd e, 0.0. (2019): The application of the vermicomposting process in the bioremediation of diesel contaminated soils, Journal of Environmental Science and Health, Part B, DOI: 10.1080/03601234.2019.1611303

[36] M. G. Pereira, Contaminac/aoambientalpelasind'ustrias de beneficiamento de caulim e avaliac/ao do emprego de vermicomposto no tratamente de efluentescontendometais [Dissertation], Federal University of Vigosa, Vicaosa, Brazil, 2000.

[37] D. Alvarez-Bernal, E. L. Garc'ia-D'iaz, S. M. Contreras-Ramos, and L. Dendooven, "Dissipation of polycyclic aromatic hydrocarbons from soil added with manure or vermicompost," Chemosphere, vol. 65, no. 9, pp. 1642-1651,2006.

[38] S. M. Contreras-Ramos, D.' Alvarez-Bernal, and L. Dendooven, "Removal of polycyclic aromatic hydrocarbons from soil amended with biosolid or vermicompost in the presence of earthworms (Eiseniafetida)," Soil Biology and Biochemistry, vol. 40, no. 7, pp. 1954-1959,2008.

[39] J. D. Fern'andez-Bayo, E. Romero, F. Schnitzler, and P. Burauel, "Assessment of pesticide availability in soil fractions after the incorporation of winery-distillery vermicomposts," Environmental Pollution, vol. 154, no. 2, pp. 330-337,2008.

[40] J. D. Fern 'andez-Bayo, R. Nogales, and E. Romero, "Improved retention of imidacloprid (Confidor) in soils by adding vermicompost from spent grape marc," Science of the Total Environment, vol. 378, no. 1-2, pp. 95-100,2007.

[41] L. Delgado-Moreno and A. Pena, "Compost and vermicompost of olive cake to bioremediatetriazines-contaminated soil," Science of the Total Environment, vol. 407, no. 5, pp. 1489-1495,2009.

[42] N. Kadian, A. Malik, S. Satya, and P. Dureja, "Effect of organic amendments on microbial activity in chlorpyrifos contaminated soil," Journal of Environmental Management, vol. 95, supplement, pp. S199-S202,2012.

[43] T. Iwamoto and M.Nasu, "Current bioremediation practice and perspective," Journal of Bioscience and Bioengineering, vol. 92, no. 1, pp. 1-8,2001.

[44] C. P. Jord~ao,W. L. Pereira, D. M. Carari, R. B. A. Fernandes, R. M. deAlmeida, andM. P. F. Fontes, "Adsorption fromBrazil ian soils of Cu(ll) and Cd (I I) using cattle manure vermicompost," International Journal of Environmental Studies, vol. 68,no. 5, pp. 719-736,2011.

[45] V. N. Kavamura and E. Esposito, "Biotechnological strategies applied to the decontamination of soils polluted with heavy metals," Biotechnology Advances, vol. 28, no. 1, pp. 61-69,2010.

[46] J. H. Park, D. Lamb, P. Paneerselvam, G. Choppala, N. Bolan, and J. Chung, "Role of organic amendments on enhanced bioremediation of heavy metal (lord) contaminated soils," Journal of Hazardous Materials, vol. 185, no. 2-3, pp. 549-574,2011.

[47] J. D. Fernandez-Bayo, R. Nogales, and E. Romero, "Assessment of three vermicomposts as organic amendments used to enhance diuron sorption in soils with low organic carbon content,"EuropeanJournaI of Soil Science, vol. 60,no. 6, pp. 935-944,2009.

[48] Alavi N, Daneshpajou M, Shirmardi M, Goudarzi G, Neisi A, Babaei AA (2017) Investigating the efficiency of co-composting and vermicomposting of vinasse with the mixture of cow manure wastes, bagasse, and natural zeolite. Waste Manag 69:117-126

[49] Martin-Gil J, Navas-Gracia LM, Gómez-Sobrino E, Correa-Guimaraes A, Hernández-Navarro S, Sánehéz-Báscones M, Ramos-Sánchez MdC (2008) Composting and vermicomposting experiences in the treatment and bioconversion of asphaltens from the Prestige oil spill. BioresourTechnol 99:1821-1829.

[50] Suleiman H, Rorat A, Grobelak A, Grosser A, Milczarek M, Ply tycz, В, Kacprzak M, Vandenbuicke F (2017) Determination of the performance of vermicomposting process applied to sewage sludge by monitoring of the compost quality and immune responses in three earthworm species: Eiseniafetida, Eiseniaandrei and Dendrobaenaveneta. BioresourTechnol 241:103-112

[51] Varma VS, Kalamdhad AS (2016) Efficiency of rotary drum composting for stabilizing vegetable waste during pre-composting and vermicomposting. Environ Process 3:829-841.

[52] Molina MJ, Soriano MD, I ng el mo F, Llinares J (2013) Stabilisation of sewage sludge and vinasse bio-wastes by vermicomposting with rabbit manure using Eiseniafetida. BioresourTechnol 137:88-97.

[53] Rorat A, Wloką D, Grobelak A, Grosser A, Sosnecka A, Milczarek M, Jelonek P, Vandenbuicke F, Kacprzak M (2017) Vermiremediation of polycyclic aromatic hydrocarbons and heavy metals in sewage sludge composting process. J Environ Manage 187:347-353.

[54] Azizi AB, Liew KY, Noor ZM, Abdullah N (2013b) Vermiremediation and mycoremediation of polycyclic aromatic hydrocarbons in soil and sewage sludge mixture: a comparative study. Int J Environ Sei Dev 4:565-568

[55] Kumar R, Verma D, Singh BL, Kumar U (2010) Composting of sugar-cane waste by-products through treatment with microorganisms and subsequent vermicomposting. BioresourTechnol 101:6707-6711.

[56] Sharma K, Garg VK (2018) Comparative analysis of vermicompost quality produced from rice straw and paper waste employing earthworm Eiseniafetida (Sav.). BioresourTechnol 250:708-715

[57] Kharrazi SM, Younesi H, Abedini-Torghabeh J (2014) Microbial biodegradation of waste materials for nutrients enrichment and heavy metals removal: An integrated composting-vermicomposting process. I ntBiodeteriorBiodeg rad 92:41-48

[58] Zhu W, Yao W, Zhang Z, Wu Y (2014) Heavy metal behavior and dissolved organic matter (DOM) characterization ofvermicomposted pig manure amended with rice straw. Environ SciPollut Res 21:12684-12692.

[59] Ceccanti B, Masciandaro G, Garcia C, Macci C, Doni S (2006) Soil bioremediation: combination of earthworms and compost for the ecological remediation of a hydrocarbon polluted soil. Water Air Soil Pollut 177:383-397.

[60] Balachandar R, Baskaran L, Yuvara] A, Thangaraj R, Subbaiya R, Ravindran B, Chang SW, Karmegam N (2020) Enriched pressmud vermicompost production with green manure plants using Eudriluseugeniae. BioresourTechnol 299:122578.

[61] Gong X, Li S, Carson MA, Chang SX, Wu Q, Wang L, An Z, Sun X (2019) Spent mushroom substrate and cattle manure amendments enhance the transformation of garden waste into vermicomposts using the earthworm Eiseniafetida. J Environ Manage 248:109263.

[62] Troeh, F. R., Hobbs, J., & Donahue, R. L. (1981). Soil and Water Conservation for Productivity and Environment Production. Soil Science, 88,299-309.

[63] Zhan, X., Wang, H., He, L., Lu, K., Sarmah, A., Li, J., Huang, H. (2013). Using Biocharfor Remediation of Soils Contaminated with Heavy Metals and Organic pollutants. Environmental Science and Pollution Research, 20,8472-8483.

[64] Cottenie, A.,&Verloo,M. (1984). Analytical Diagnosis of Soil Pollution with Heavy Metals. Environmental Research and Protection.

[65] Blum, W. E. (1990). The Challenge of Soil Protection in Europe. Environmental Conservation, 17,72-74.

[66] Lente, L, Keraita, B., Drechsel, P., Ofosu-Anim, J., & Brimah, A. K. (2012). Risk Assessment of Heavy Metal Contamination on Vegetables Grown in Long-Term Wastewater Irrigated U i ban Fa i ming Sites in Accra, Ghana. Water Quality Exposure and Health, 4,179-186.

[67] Muchuweti, M., Birkett, J., Chinyanga, E., Zvauya, R., Scrimshaw, M. D., & Lester, J. (2006). Heavy Metal Content of Vegetables Irrigated with Mixture of Wastewater and Sewage Sludge in Zimbabwe: Implications of Human Health. Agricultural Ecosystem and Environment, 112,41-48.

[68] Khan, S., Cao, Q., Zheng, Y., Huang, Y., & Zhu, Y. (2008). Health Risk of Heavy Metals in Contaminated Soils and Food Crops Irrigated with Wastewater in beijing, China. Environmental Pollution, 152,686-692.

[69] Zhuang, P., McBride, M. B., Xia, H., Li, N., & Li, Z. (2009). Health Risk from Heavy Metal via Consumption of Food Crops in the Vicinity of Dabraoshan Mine, South China. Science of the Total Environment, 407,1551-1561

[70] Frick, C. M., Farrell, R. E., & Germida, J. J. (1999). Assessment of Phytoremediation as as In-Situ Technigues for Cleaning Oil Contamination Sites. University of Saskatchewan, Department of Soil Science. Saskatoon: Petroleum Technology Alliance Canada. Retrieved March 21,2020.

[71] Kang, Y. S., Park, Y. J., Jung, J., & Park, W. (2009). Inhibitory effect of aged petroleum hydrocarbons on the survival of inoculated microorganisms in a crude-oil contaminated site, journal of microbiology and Biotechnology, 19,1672-1678

[72] Townsend, G. T., Prince, R., & Suflita, J. (2003). Anaerobic Oxidation of Crude Oil Hydrocarbons by the Resident Microorganisms ofa Contaminated Anoxic Aguifer. Environmental Science and Technology, 37(22), 5213-5218. doi:10.1021/es0264495

[73] Labud, V., Garcia, C., & Hernandez, T. (2007). Effect of Hydrocarbon Pollution on the Microbial Properties of a Sandy and a Clay Soil. Chemosphere, 66(10), 1863-1871.

[74] Sutton, N. B., Maphosa, F., Mirii Io, J. A., Al-Soud, W. A., Langenhoff, A. M., Grotenhuis, T. and Smidt, H. (2013). Impact of Long-Term Diesel Contamination on Soil Microbial Community Structure. Applied and Environmental Microbiology, 79(2), 619-630. doi:10.1128/AEM.02747-12

[75] Giiler, K. E., Witter, E., & McGrath, S. P. (1998). Toxicology of Heavy Metals to Mocroorganismsand Microbial Processes in Agricultural Soils: a review. Soil Biology and Biochemistry, 30,1389-1414.

[76] Hyne, N. J. (2012). Nontechnical Guide to Petroleum Geology, Exploration, Drilling and Production. Tulsla, Oklahoma: Library of Congress Cataloging-in-Publication Data

[77] Njoku, K. L, Nomba, E. U., & Olatunde, A. M. (2017). Vermiremediation of Crude Oil Contaminated Soil Using Eudrillus euginae and Lumbriscus terrestris. Journal of Biological and Environmental Science, 11 (31), 43-50.

[78] Kabata-Pendias A., Pendías H., (2001), Trace Elements in Soils And Plants, CRC Press, London

[79] Jadia, C. D. and Fulekar, M. H. (2008). Phytoremediation: The Application of Vermicompost to Remove Zinc, Cadmium, Copper, Nickel and Lead By Sunflower Plant. Environmental Engineering and Management Journal. Vol.7, No.5,547-558